GCF for 8, 21 and 75

"Greatest Common Factor of 3 Numbers" Calculator
Greatest Common Factor of
,
and

What's the Greatest Common Factor (GCF) of 8, 21 and 75?

Answer

GCF of 8, 21 and 75 is
1

Common factors: 1

Only 1 divides all three: no prime is a factor of each of 8, 21 and 75.

Pairs do share factors — GCF(21, 75) = 3 — just none greater than 1 common to all three.

8 = 23

21 = 3 × 7

75 = 3 × 52

Prime82175Lowest power
223———
3—33—
5——52—
7—7——

— = power 0: the prime is not a factor of this number, so it cannot be in the GCF.

GCF = 1

More with these numbers

Related Calculations

See Also

GCF Table

1st2nd3rdGCF
821601
821611
821621
821631
821641
821651
821661
821671
821681
821691
821701
821711
821721
821731
821741
821751
821761
821771
821781
821791
821801
821811
821821
821831
821841
821851
821861
821871
821881
821891

FAQ

What's the Greatest Common Factor (GCF) of 8, 21 and 75?

GCF of 8, 21 and 75 is 1

What prime factors do 8, 21 and 75 share?

None at all: 8, 21 and 75 have no prime factor in common, so the only positive integer dividing all three is 1 and their GCF is 1.

Can you get the GCF of 8, 21 and 75 two numbers at a time?

Yes. The GCF of 8 and 21 is 1, and the GCF of 1 and 75 is 1 — the same answer, because the greatest common factor is associative and does not depend on the order of the three numbers.

How does the GCF simplify the ratio 8 : 21 : 75?

Divide every term by the GCF 1: 8 ÷ 1 = 8, 21 ÷ 1 = 21 and 75 ÷ 1 = 75. So 8 : 21 : 75 in lowest terms is 8 : 21 : 75, and no whole number other than 1 divides all three of those.

See Also